// pod's hosts file.
message HostAlias {
  // IP address of the host file entry.
  optional string ip = 1;

  // Hostnames for the above IP address.
  repeated string hostnames = 2;
}

// Represents a host path mapped into a pod.
// Host path volumes do not support ownership management or SELinux relabeling.

- The new test `[sig-network] DNS should now provide /etc/hosts entries for the cluster [LinuxOnly] [Conformance]` will validate the host entries set in the ``/etc/hosts`` file (pod's FQDN and hostname), which should be managed by Kubelet. ([#72729](https://github.com/kubernetes/kubernetes/pull/72729), [@bclau](https://github.com/bclau))

  * A new field hostAliases has been added to the pod spec to support [adding entries to a Pod's /etc/hosts file](https://kubernetes.io/docs/concepts/services-networking/add-entries-to-pod-etc-hosts-with-host-aliases/). ([#44641](https://github.com/kubernetes/kubernetes/pull/44641), [@rickypai](https://github.com/rickypai))

  - [Changelog since v1.21.4](#changelog-since-v1214)
  - [Important Security Information](#important-security-information)
    - [CVE-2021-25741: Symlink Exchange Can Allow Host Filesystem Access](#cve-2021-25741-symlink-exchange-can-allow-host-filesystem-access)
  - [Changes by Kind](#changes-by-kind-8)
    - [Feature](#feature-6)
    - [Bug or Regression](#bug-or-regression-8)

 
## Changes by Kind

### Bug or Regression

- CVE-2020-8557 (Medium): Node-local denial of service via container /etc/hosts file. See https://github.com/kubernetes/kubernetes/issues/93032 for more details. ([#92916](https://github.com/kubernetes/kubernetes/pull/92916), [@joelsmith](https://github.com/joelsmith)) [SIG Node]

### Bug or Regression

- CVE-2020-8557 (Medium): Node-local denial of service via container /etc/hosts file. See https://github.com/kubernetes/kubernetes/issues/93032 for more details. ([#92916](https://github.com/kubernetes/kubernetes/pull/92916), [@joelsmith](https://github.com/joelsmith)) [SIG Node]

- Kubeadm: switch the preflight check (called 'Swap') that verifies if swap is enabled on Linux hosts to report a warning instead of an error. This is related to the graduation of the NodeSwap feature gate in the kubelet to Beta and being enabled by default in 1.23 - allows swap support on Linux hosts. In the next release of kubeadm (1.24) the preflight check will be removed, thus we recommend that you stop using it - e.g. via `--ignore-preflight-errors`...

  and removed `--short` flag entirely. ([#116720](https://github.com/kubernetes/kubernetes/pull/116720), [@soltysh](https://github.com/soltysh))
- Kube-controller-manager deprecate `--volume-host-cidr-denylist` and `--volume-host-allow-local-loopback` flags. ([#118128](https://github.com/kubernetes/kubernetes/pull/118128), [@carlory](https://github.com/carlory)) [SIG API Machinery, Apps, Network, Node, Storage and Testing]

* Refactor addons into multiple packages ([#50214](https://github.com/kubernetes/kubernetes/pull/50214), [@andrewrynhard](https://github.com/andrewrynhard))
* Kubelet now manages `/etc/hosts` file for both hostNetwork Pods and non-hostNetwork Pods. ([#49140](https://github.com/kubernetes/kubernetes/pull/49140), [@rickypai](https://github.com/rickypai))

- Service Controller: will now update load balancer hosts after node's `ProviderID` is
  updated. ([#120492](https://github.com/kubernetes/kubernetes/pull/120492), [@cezarygerard](https://github.com/cezarygerard))